Compressibility of hard-hexagon lattice gas model.

Terms

a(0) =1a(1) =-7a(2) =18a(3) =-24a(4) =24a(5) =6a(6) =66a(7) =258a(8) =1014a(9) =3906a(10) =14760a(11) =54696a(12) =198510a(13) =704010a(14) =2431110a(15) =8130096a(16) =26103624a(17) =79292226a(18) =221534442a(19) =532863372a(20) =870102906a(21) =-842584128a(22) =-17420140980a(23) =-111985825752a(24) =-559952980782